Flexing and spin flanging of can body edges



I March 3, 1970 A. HANssdN FLEXING AND SPIN FLANGING 'OF CAN BODY EDG'ES Filed Feb. 24. 1966 4 Sheets-Sheet '1 March 31970 I "-A.- HANSSON I 3,498,245

' v FLEXING AND SPIN FLANGING 0F CAN'BODY EDGES Fi1ed feb, 24,1966 v 4 Sheets-Sheet s 96 r nos I mv II I t \n INVENTOR Am: Hanan/2 M; Ma

ATTORNEYS HANSSON FLEXING AND SPIN FLANGING OF CANTBODY EDGES Filed Feb. 24. 1966 March 3,1910

4 Sheets-Sheet 4 I: c1.2l

" ISI I40 I37 I36 INVENTOR Am: Hausa/2 W443i, Jada/8' ATTORNEYS.

United States Patent Int. Cl. BZld 19/04 US. Cl. 113-120 This is a continuation-in-part application of Ser. No. 273,598, filed Apr. 17, 1963 and now abandoned.

7 Claims This invention relates to a novel method for flexing and spin flanging edges of substantially tubular metallic bodies to increase the transverse ductility of the edges, and in particular, to a novel method for flexing and spin flanging the edges of high-strength brittle metallic can bodies by subjecting incremental portions of the can body edges to rapidly reversing tension and compression forces According to present can making technology it is necessary to form a flange at both ends of a can body for subsequently seaming on a can end or cover at each of the flanged ends of the can body. Flanging is presently done with a die having a widening contour which when forced into a can body deflects the metal at the edges of the can body over the widening contour of the die to expand the metal outward and normal to the axis of the can body. This flanging method, called die flanging or dynamic flanging, produces a circumferential flange of approximately 0.1 inch width or more.

Die flanging or dynamic flanging subjects the entire circumference of the edge of the can body to tension forces which tend to crack the circumferential flanges of the can bodies during the flanging operation, This tendency of cracks developing in the flanges of the can bodies during the dynamic flanging thereof is lessened when the can bodies are made of metal which is relatively low tempered and ductile. However, dynamic flanging cannot be used to flange metallic can bodies which are made of certain new materials, such as very thin grades of double reduced or hard rolled metallic plates.

Can bodies which are made of fully hardened steel plate and certain aluminum and aluminum alloys of hard tempers are not susceptible to die flanging or dynamic flanging because these materials are so brittle that the edges of the can bodies crack during the flanging operation. This is especially true with two welded can bodies which, of necessity, are made from H-grain metal i.e., the metal rolling direction being parallel to the height of the can body. Dynamic flanging of two welded can bodies produces cracks which are numerous, sever and fre quently extend well down into the can body. Since these brittle materials are very attractive in the can making industry from the standpoint of strength and cost-ofmaterial, a new method of flanging these newer brittle, less ductile hard tempered materials was developed and is the novel subject matter of this application.

It is, therefore, an object of this invention to provide a novel method of flexing and flanging substantially tubular metallic bodies, such as can bodies, made from relatively brittle metallic material which has heretofore been generally incapable of being flanged by present-day die flanging or dynamic flanging methods.

A further object of this invention is to provide a novel method of flanging tubular can bodies constructed of metallic material by supporting a tubular can body so as to leave at least one circumferential end portion of the body at all times free and unsupported, directing a plurality of forces against the interior of the unsupported end portion to effect rapidly reversing tension and compression forces in incremental surface areas of the un- 3,498,245 Patented Mar. 3, 1970 supported end portion whereby the outer surface at the circumferential end portion is first strained beyond the yield point during the tension portion of the reversing cycle, and thereafter subjecting the end portion to forces which cause only circumferential deformation whereby the end portion is radially outwardly flanged during the same time it is subjected to thecircumferential deformation whereby the end portion is transformed into a flange in the absence of flange cracking.

A further object of this invention is to provide a novel method of flanging tubular can bodies in the manner immediately above described wherein the can body includes an opposite circumferential end portion, and the opposite circumferential end portion is subjected to forces similar to those directed against the first-mentioned circumferential end portion whereby the circumferential end portions are simultaneously transformed into flanges in the absence of flange cracking.

With the above and other objects in view that will hereinafter appear, the nature of the invention will be more clearly understood by reference to the following detailed description, the appended claims and the several views illustrated in the accompanying drawings.

In the drawings:

FIGURE 1 is a fragmentary elevational view of a flexing head constructed in accordance with this invention, and illustrates a plurality of rollers rotatably journalled in a frustoconical portion of the flexing head, and the position of the flexing head prior to being advanced into engagement with an edge of a can body clamped in a split holder.

FIGURE 2 is an enlarged fragmentary vertical sectional view of the flexing head of FIGURE 1, and illustrates the construction of the flexing head and the rollers thereof in contact with the edge of the can body.

FIGURE 3 is a fragmentary sectional view taken along line 3-3 of FIGURE 2, and illustrates each of six rollers in contact with a relatively small area of the edge of the can body and subjecting each of the small areas to rapidly fluctuating tension and compression forces.

FIGURE 4 is a fragmentary elevational view partially in crosssection and illustrates a novel spin flanging head constructed in accordance with this invention including a body carrying a pair of diametrically opposed rollers, each of the rollers being circumferentially grooved, and the position of the rollers with respect to an edge of a metallic can body at the termination of a spin flanging operation.

FIGURE 5 is a fragmentary elevational view partially in cross-section, and illustrates a pair of the spin flanging heads of FIGURE 4 positioned at opposite ends of a can body at the termination of a spin flanging operation.

FIGURE 6 is a fragmentary elevational view partially in cross-section, and illustrates another spin flanging head constructed in accordance with this invention, the spin flanging head including a plurality of substantially conical shaped rollers in engagement with an edge of a metallic can body secured in a split holder.

FIGURE 7 is a cross-sectional view taken along line 77 of FIGURE 6, and illustrates the conical rollers subjecting incremental portions of the edge of the can body to rapidly reversing tension and compression forces.

FIGURE 8 is a fragmentary sectional view taken along line 8-8 of FIGURE 6, and more clearly illustrates the contact between the conical rollers and the edge of the can body.

FIGURE 9 is an enlarged fragmentary sectional viewtaken along line 99 of FIGURE 7, and illustrates one of the plurality of conical rollers rotatably journalled in the spin flanging head and the formation of a flange 3 from the material of the edge of the can body by the conical rollers.

FIGURE is a vertical elevational view of another spin flanging head, and illustrates two of three conical rollers, similar to the conical rollers of FIGURE 6 through 9, carried by the spin flanging head.

FIGURE 11 is a bottom view of the spin flanging head of FIGURE 10, and illustrates the three conical rollers, similar to the conical rollers of FIGURES 6 pared to the conical rollers of FIGURES 6 and 7.

FIGURE 12 is a fragmentary elevational view of a flexing head, and illustrates a plurality of groups of rollers of the flexing head in contact with an edge of a can body held in a splitholder.

FIGURE 13 is an enlarged sectional view taken along line 13-13 of FIGURE 12 and illustrates three groups of rollers with three rollers in each group and the position of the can body edge with respect to the groups of rollers during the flexing operation.

FIGURE 14 is an enlarged fragmentary sectional view taken along line 1414 of FIGURE 13, and illustrates the flexing of the can body edge during the rotation of the flexing head of FIGURES 12 and 13.

FIGURE is a fragmentary elevational view of another spin flanging head constructed in accordance with this invention, and illustrates the spin flanging head rotating and descending into a can body held in a split holder and the initial engagement of the spin flanging head with an edge of the can body.

FIGURE 16 is a fragmentary enlarged sectional view FIGURE 18 is a fragmentary elevational view of another flexing head of this invention, and illustrates a plurality of cylindrical elements carried in a cavity of the flexing head in engagement with an edge of a can body held in a rotating split holder.

FIGURE 19 is an enlarged sectional view taken along line 1919 of FIGURE 18, and illustrates the upper edge of the can body being subjected to rapidly reversing tension and compression forces tending to partially flange the edge of the can body radially inwardly toward the aXis thereof.

FIGURE is a fragmentary sectional view taken along line 20-20 of FIGURE 19, and more clearly illustrates the coaction between the spin flanging head and the edge of the can body held by the split holder.

FIGURE 21 is a fragmentary sectional view taken along line 2121 of FIGURE 20, and illustrates each of the elongated elements of the spin flanging head effecting an incremental area of the edge of the can body.

FIGURE 22 is a fragmentary sectional view of a roller flanger, and illustrates an edge of a brittle metallic can body which has been previously flexed by any one of the flexing heads heretofore illustrated being flanged by the roller flanger.

As has been heretofore noted, die flanging or dynamic flanging subjects the entire edge of a can body to tension forces. These tension forces cause elongation of the edge of the can body and, as an example, the edge of a number 211 can body having a two and eleven sixteenth inch body diameter is elongated approximately 8% in the transverse direction of very low ductility. High strength double reduced and full hard plate cannot be elongated by more than 1 to 1.5%, thus indicating that the flanging of can bodies from these high strength materials without producing cracks would be an impossibility. However, while the tensile elongation of these high strength materials does not exceed 1 to 1.5% when measured over a normal gauge length of two inches, the tensile elongation may go up to 50% and beyond when measured over a very short gauge length adjacent to fractures or cracks produced in these brittle high strength materials When dynamic die flanging has been attempted. This extreme elongation of even brittle material in highly localized areas of fracture indicates that brittle high strength plates can be flanged by forming the edges of can bodies of a very short length. That is, by forming or deforming the edges of the can bodies constructed from relatively brittle material by successively stretching adjacent short increments of the brittle metal, long lengths of this brittle material can be elongated or stretched to a considerable extent.

Thus, the chief characteristic of this invention which is to be immediately described hereafter is that only a small increment of the metallic material at the edge of a can body is formed at one time and the forming is done by, in effect progressively moving this increment rapidly around the circumference of the edge of the can body.

The invention will be best understood and described by first referring to FIGURES 1 through 3 of the drawings to which attention is now directed. A substantially tubular, metallic can body 10 having an upper peripheral edge 11 is locked in a conventional split holder 12 having a base 13 anchored to a supporting surface 14. The can body 10 is made from relatively brittle metallic material, such as double reduced or hard rolled plate which is relatively brittle in the as-received condition thereof, or high strength (brittle) aluminum.

The can body 10 is adapted to have an end or closure (not shown) secured to opposite open end portions (unnumbered) thereof by, for example, a double seam. However, the can body 10 can be impact extruded from aluminum or similar material whereby the can body would have one integral closed end and an opposite open end to which a closure may be secured by, for example, a double seam or welding. In this case a can formed from such an impact extruded can body would be of a two-piece construction i.e., the can body and one closure.

The thickness of the material of the can body is preferably between .006.008 inch, but is not greater than .015 inch. The tensile elongation of the material is in most cases approximately 3% elongation when measured over a normal gauge length of two inches, but may range between 1-8% elongation over the same length gauge.

A flexing head or flexer head 15 is reciprocally and rotatably mounted in axial alignment with the can body 10 in a manner which is conventional and is therefore not illustrated. The flexing head 15 is normally positioned in spaced relationship to the edge 11 of the can body 10, and is mounted for reciprocal movement into and out of the can body 10, as is indicated by the double-headed arrow of FIGURE 1.

The flexing head 15 includes a body 16 having a frustoconical surface 17 defined by a generatrix of the body 16. An upwardly opening concavity 18 is separated from a downwardly opening concavity 20 by a central Wall 21 of the body 16. A rotatable shaft 22 is secured to the body 16 of the flexing head 15.

The rotatable shaft 22 includes an integral, annular, stop collar 23 and a reduced threaded end portion 24 projecting through an axial aperture 25 in the central wall 21 of the body 16. A substantially frustoconical clamping plate 26 is provided with a bore 27 for receiving the reduced end portion 24 of the shaft 22. A counterbore 28 in the clamping plate 26 forms a recess for receiving a nut 30 threaded upon the reduced end portion 24 of the shaft 22. I

The frustoconical surface 17 of the body 16 is provided with a plurality of identical semi-cylindrical grooves or slots 31. The semi-cylindrical grooves or slots 31 are parallel to the generatrices of the body 1.6.

An identical, substantially elongated, cylindrical element or roller 32 is received in each of the semi-cylindrical grooves 31. The semi-cylindrical grooevs 31 and the rollers 32 received therein are equally spaced along the frustoconical surface 17 of the body 16, as is best illustrated in FIGURES 1 and 3 of the drawings. Each of the rollers 32 includes a shaft 33 journalled between the clamping plate 26 and the body 16 of the flexing head 15 in a manner clearly illustrated in FIGURE 2 of the drawings. A cylindrical surface 34 of each of the rollers 32 projects outwardly of the semi-cylindrical grooves 31 beyond the frustoconical surface 17 of the body 16.

As the flexing head 15 is rotated it is reciprocated from a position spaced from the edge of the can body to the position illustrated in FIGURE 1, wherein each of the rollers 32 barely contacts the edge 11 of the can body 10. Continued downward reciprocation of the flexing head forces each of the rollers 32 into intimate contact with the edge 11 of the can body 10. At the instant the rollers 32 begin to bear against the edge 11 of the can body 10, the edge 11 begins losing its cylindrical cross-sectional configuration and begins to approach the polygonal cross-sectional configuration of the edge 11 shown in FIG- URE 3 of the drawings. At the corners of the now polygonal edge 11, the edge 11 of the can body 10 is conformed to the surface 34 of each of the rollers 32. At any one instant an incremental area I of the outer surface of the edge 11 in contact with the surface 34 of each of the rollers 32 is placed in tension while the straight portion between these incremental portions or areas are placed in compression. This is diagrammatically represented in FIGURE 3 of the drawings by the positive signs indicating tension and the negative signs indicating compression at the outer surface of the can body edgeportion 11. While the positive and negative signs have been illustrated only along the exterior surface of the body 10, it is to be understood that the inner surface (unnumbered) of the edge 11 is also subjected to stresses. However, in this case in any one instant an outer incremental area, corresponding to the areas I, of the edge 11 in contact with the inner surface of each of the rollers 32 is placed in compression While the straight portion between these incremental portions or areas is placed in tension. This can be visualized in FIGURE 3 of the drawings by imagining that the positive and negative signs are reversed and are illustrated at the inner surface of the can body edge 11.

With the flexing head rotating, the stress state at each of the incremental portions I reverses rapidly so that all surface portions of the edge 11 will. alternately be in tension and compression. Thus, the edge 11 of the body is 0 placed in tension only at those areas or portions which at a given instant are in contact with the surfaces 34 of the rollers 32. Only the relatively small incremental portions I of the metallic edge 11 are being formed at one time and the forming is done progressively by rotating the flexing head 15 which, in effect, moves this increment rapidly around the edge 11 of the can body 10.

During the initial descent of the flexing head 15 which effects the rapidly reversing tension and compression forces at the incremental areas I of the unsupported end portion 11, the material is strained beyond the yield point thereof during the tension portion of the reversing cycle. It is during this initial phase of the method that the outer surface is subjected to reversing tension and compression forces, but subsequently the compressive strains are reduced and disappear until the end portion 11 is subjected only and completely to tension forces or strength which cause circumferential deformation and the subsequent flanging of the end portion 11.

The incremental portion I of the edge 11 which is under tension during any instant corresponds to the arc of contact between the surface 34 of each of the rollers 32 and the edge 11. This incremental area should be minimized as much as possible to achieve maximum elongation or stretching of the middle material of the can body 10 in the area of the edge 11. The number of rollers 32,

on the other hand, should be large because otherwise the entire can body would tend to polygonize when the flexing head 15 is forced into the can body 10 and the resultant excessive flexing of the edge 11 as well as the entire can body 10 could fracture the edge 11. To achieve a minimum arc of contact between the rollers 32 of the flexing head 15 and the edge 11 of the can body 10 the rollers 32, as heretofore noted, are positioned with an axes parallel to the generatrix of the body 16. Each of the rollers 32 is thus oriented at an angle of approximately 45 degrees with respect to the axis of the can body 10. This positioning of the rollers 32 reduces the arc of contact between the surfaces 34 of the rollers 32 and the edge 11 of the can body 10', as is best illustrated in FIGURE 3 of the drawings. Each of the six rollers 32 has a diameter D which is preferably one-quarter of an inch. However, because of the inclination or slanting of the rollers 32 with respect to the axis of the can body 10, the area of contact or incremental portion I of the edge 11 is appreciably less than the diameter D of the rollers 32. The slant or oblique mounting of the rollers 32 has the beneficial effect apparently reducing the roller diameter and the incremental area of contact I with the edge 11 of the can body 10 so that, depending upon the angle of the generatrix of the body 16, a one-quarter inch roller may do the work normally done by a one-eighth inch roller.

After the flexing head 15 is withdrawn from the can body 10, the edge 11 is partially flanged. That is, as is best illustrated in FIGURE 2 of the drawings, the edge 11 of the can body 10 is circumferentially flanged at an angle of approximately 45 degrees to the axis of the can body 10. In order to complete the flanging of the can body 10 the edge or flange 11 has to be turned out so that it forms the can end receiving flange, i.e., a circumferential flange which is normal to or disposed at a degree angle to the axis of the can body 10. One way of accomplishing this is by incorporating a properly designed groove into each of the cylindrical rollers 32 of FIG- URES 1 through 3 of the drawings. An example of an apparatus for forming a 90 degree flange with respect to a can body is shown in FIGURE 4 of the drawings, and is generally designated by the reference numeral 35.

The apparatus 35 is termed a spin flanging head or flex flanging head since in operation it simultaneously subjects a can body to rapidly reversing tension and compression forces and forces which effect full 90 degree radial flanging of an edge of the can body.

The spin flanging head 35 includes a body 36 secured to a shaft 37 which is reciprocated and rotated in a conventional manner.

The body 36 includes a pair of identical, diametrically opposed arms 38. An identical elongated element or roller 40 is journalled to each of the arms 38 by a bolt 41 threadably received in a threaded aperture 42 of the arms 38. An identical washer 43 is positioned between each of the rollers 40 and an associated arm 38 to reduce frictional forces during a spin flanging operation.

Each of the rollers 40 is provided with a medial circumferential groove 44 contoured to produce a flan e turned out at an angle of 90 degrees to the axis of the can body 10.

Each of the rollers 44 subjects the edge 11 of the can body 10- to rapidly reversing tension and com ression forces in a manner substantially identical to that discussed in connection with FIGURES 1 through 3 of the drawings. and in addition, each of the grooves 44 eifects full 90 degree radial flanging of the edge 11 with respect to the axis of the body 10. Since only two rollers 44in diametrically opposed relationship flex and flange the can body 10 of FIGURE 4, the can body 10 is su ported by the split holder 12 nearer the edge 11 than in FIGURE 1. By thus supporting the can body 10 nearer to the edge 11 the latter is not excessively polygonized and flanges are eventually produced without cracks in the material of the can body.

While only two rollers 40 are shown in FIGURE 4 of the drawings, additional rollers identical to the rollers 40 may be provided by merely constructing the body 36 of a frustoconical configuration and securing the additional rollers to the inner peripheral surface of the frustoconical body.

It should be particularly noted that the operation of the flexing head and the spin flanging head employ the common characteristic of forming or deforming a small increment of the edge 11 of the can body 10 at one instant and, in effect, progressively moving this increment rapidly around the can body 10. That is, extremely minor Succeeding incremental portions I are successively subjected to tension and compression strains at the surfaces thereof during the spinning of the spin flanging head 35 to subsequently from the full 90 degree flange edge 11. In each case the heads 15, 35 subject incremental portions of the can edges 11 to rapidly reversing tension and compression forces and the particular nomenclature of these heads is merely indicative of the extent of can edge flanging. Thus, the incorporation of a groove similar to the grooves 44 in each of the rollers 32 of the flexing head 15 would convert the flexing head 15 into a spin flanging head, while the elimination of the grooves 44 and the rollers of the spin end flanging head 35 would form a flexing head.

A flex-flanging or spin flanging head 45 is illustrated in FIGURES 6 through 9 of the drawings. The spin flanging head 45 includes a substantially cylindrical disklike body 46 secured to a rotatable and'reciprocal shaft 47 by a key 48 (see FIGURE 7). The disk-like body 46 includes a top surface 50, a bottom surface 51 and a peripheral surface 52.

Ten identical, substantialy elongated elements or rollers 53 are journalled in the disk-like body 46. The rollers 53 are equally spaced about the circumference of the disk-like body 46 adjacent the peripheral edge 52'thereof.

As is best illustrated in FIGURE 9 of the drawings, each of the rollers 53 includes a shank 54 having a reduced threaded end portion 55. The shank 54 of each of the rollers 53 passes freely through a bore 56 in the body 46 and is secured thereto by a nut 57 threaded to the reduced end portion .of the shank 54. An identical washer 58 is positioned between each of the nuts 57 and the top surface 50 of the body 46.

A ball bearing mount 60 including an inner race 61, an outer race 62 and a plurality of balls 63 is positioned in a' counterbore 64 of the body 46 and rotatably journals each of the rollers 53 in a manner clearly illustrated in FIGURE 9 of the drawings.

Each of the rollers 53 includes a lower conical portion 65, an intermediate frustoconical portion 66 and a contoured annular upper portion 67. The frustoconical portion 66 is substantially tangential to and merges with the annular upper portion 67, as is clearly illustrated in FIGURE 9 of the drawings. A cylindrical portion 68 of each of the rollers 53 provides clearance between the lower surface 51 of the body 46 and the contoured annular portion 67 of each of the rollers 53. The axis of each of the rollers 53 is also substantially normal to the bottom surface 51 of the disk-like body 46, as well as to the direction of rotation thereof as will be more apparent hereafter.

The operation of the spin flanging head 45 is substan-' tially identical to the operation of the spin flanging head 35 heretofore discussed. As the shaft 47 and the disklike body 46 carried thereby is reciprocated to the position illustrated in FIGURE 6 of the drawings, the edge 11 of the can body 10 held in the split holder 12 is first subjected to reversing tension and compression forces or strains during the time the edge is in engagement with the frustoconical portions 66 of the rollers 53. Upon engaging the contoured annular upper portion 67 of the rollers the edge 11 is thereafter subjected ,only to tension forces and is circumferentially deformed to form a radially out- 8 wardly directed flange, as is clearly illustrated in FIGURE 9 of the drawings.

The operation of the spin flanging head 45 is diagrammatically illustrated in FIGURE 8 of the drawings'which shows the frustoconical portions 66 of each .of the rollers 53 in contact with an incremental portion or area I of the can body edge 11 during the initial descent of the flanging head 45 into the can body 10. Due to the rotation of the body 46 the incremental portions are progressively subjected to the rapidly reversing tension and compression forces heretofore noted and, in addition, the continued advancement of the body 46 bring the periphery of the can body edge 11 into contact with the contoured annular portions 67 of each of the rollers 53 at which time the edge 11 is subjected only to tension forces which causes the subsequent deformation and flanging of the can body edge.

Attention is now directed to FIGURE 5 of the drawings which illustrates a can body 10 positioned in a split holder 12. The can body 10 has opposite circumferential edge portions 11, 11a and spin flanging heads 45, 45a are illustrated as being fully received in the opposite end portions adjacent each of the respective edge portions 11, 11a. The spin flanging heads shown in FIGURE 5 are identical in function and operation to the spin flanging head 45 of FIGURES 6- through 9 of the drawings. However, it should be noted that the spin flanging heads are shown being rotated in opposite directions which is desirable if the split holder 12 clampingly supporting the can body 10 is eliminated. In this case, the opposite rotation of the flanging heads 45, 4511 would effect the formation of flanges at opposite end portions of the can body 10 without the need of supporting the can body by any means whatever. If the split holder 12 is employed to clampingly retain the can body 10 and prevent the same from rotating, the flanging heads 45, 45a may, if desired, be rotated in identical directions. Thus, in this manner a can body can be simultaneously flanged at opposite axial end portions thereof.

The can body 10 illustrated in FIGURES 5 through 9 of the drawings is a 2.11 can body. That is, the diameter of the can body is two and nine sixteenths inches and the circumference is approximately 8.5 inches. The ten rollers 53 for each 2.11 inch diameter or 8.5 inch circumference have been found to work quite ideally, but any number of rollers from six to the maximum number of rollers which will fit into the interior of a can body without interference with each other may be incorporated in the flanging heads 45, 45a. Insofar as smaller diameter can bodies are concerned, one roll per inch of circumference is preferable while for larger can bodies successful flanging can be accomplished by flange heads corresponding identically to the flange head 45 but incorporating one roll for each four inches of can body circumference. The portions 66 of the rollers 53 are of varied diameters but the main diameter thereof is preferably three eighth inch, and successful flanging is achieved by preferably revolving each flange head 45, 45a between two or ten revolutions per flange. Less desirable flanging can be accomplished between one-half to twentyfive revolutions per flange and it is, of course, to be understood that irrespective of the number of revolutions required to form a particular flange, it is necessary during the revolutions to progressively force the rollers 53 into successive contact with the partitions 66, 67 of the rollers 53.

During the initial insertion of the rollers 53 into the can body 10 (FIGURE 6) each of the surfaces 66 is in minute point contact with the circumferential edge portion 11 of the can body 10. However, as the rollers 53 are progressively inserted into the can body 10, the surfaces 66 progressively contact larger incremental areas I until maximum incremental areas are contacted by the portions 67 of the rollers 53 at the termination of the spin flang ng operation at which time the flange has been completely formed. Thus, the incremental areas I which are contacted by the rollers 53 progressively increase from point contact at the beginning of the spin flanging to more appreciable contact at the termination of the flanging operation. The maximum length of the incremental areas I as measured in a circumferential direction when a 2.11 can body is spin flanged by the spin flanger 45 has been measured and is substantially onesixteenth inch in length. Thus, at one instant during which the rollers 53 are in contact with the edge 11 of a 2.11 can body only five-eighth inch (ten rollersX Aa inch per roller) of roller surface is in contact with the edge portion 11 which is, of course, approximately 8.5 inches in circumference. As will be readily apparent, the circumferential length of the incremental areas I will vary de pending upon the number of rollers, the diameter of the rollers, etc. However, in accordance with this invention, the maximum contact between any one roller and the edge portion 11 is preferably no greater than three-sixteenths inch.

A spin flanging head 70, similar to the spin flanging head 45 of FIGURES 6 through 9, is illustrated in FIG- URES and 11 of the drawings. The spin flanging head 70 includes a cylindrical disk-like body 71 secured to a rotatable and reciprocal shaft 72 by a key (not shown) similar to the key 48 of FIGURE 7. The disk-like body 71 includes a top surface 73, a bottom surface 74 and a peripheral surface 75. Three identical elongated elements or conical rollers 76, 77 and 78 are journalled through the disk-like body 71 of the spin flanging head 70 in a manner identical to that illustrated in FIGURE 9 of the drawings. The axis of each of the substantially conical rollers 76 through 78 is normal to the bottom surface 74 of the body 7.1, and each of the conical rollers 76 through 78 includes a lower conical portion 80, an intermediate frustoconical portion 81, a contoured annular portion 72 and a cylindrical clearance portion 83 The flanging head 70 of FIGURES 10 and 11 differs from the spin flanging head 45 of FIGURES 6 through 9 in two aspects. First, the maximum diameter of each of the frustoconical portions 81 of the rollers 76 through 78 is one inch while the maximum diameter through each of the frustoconical portions 66 of the rollers 53 is onequarter, inch. Secondly, there are only two rollers 76 through 78 carried by the head 70 whereas the head 45 carries ten rollers. The reduced number of rollers of the spin flanging head 70 requires that a can body being flanged thereby must be gripped closely adjacent an edge thereof for the reasons heretofore discussed in connection with FIGURE 4. That is, while polygonization is desirable and necessary during the operation of any one of the flanging heads of this invention, excessive polyg onization is just as much undesirable due to the tendency of the can body edge portions 10 to rapidly fluctuate and eventually crack when stressed only at a very few points by a minimum number of rollers. Secondly, the spin flanging head 70 must be rotated a number of times more than the spin flanging head 45 to achieve a smooth flange. Otherwise, the spin flanging head 70 operates in a manner identical to that heretofore discussed in the description of FIGURES 1 through 9 of the drawings, and a further discussion of the operation of the spin flanging head 70 is deemed unnecessary.

It is desirable at times to condition the edge of a can body constructed from relatively brittle metal by subjecting the edge to rapidly reversing tension and compression forces without forming a partial or a full flange, as in the devices heretofore described. For example, where an end has been seamed to a can body or the can body is formed by a drawing operation, it is desirable to condition or flex the open end of the can body because flanges tend to become damaged during shipment to a packaging plant. While the packaging plant may be equipped with conventional die flanging apparatus, these brittle can bodies cannot be flanged. Therefore, by first flexing the edges of these can bodies without forming flanges, the conventional flanging apparatus at the packaging plant may be employed to flange the can bodies and damage to preformed flanges is eliminated.

A flexing head shown in FIGURES 12 and 13 of the drawings is designed to flex an edge of a can body without flanging the same.

The flexing head 85 includes a disk-like body 86 secured to a rotatable and reciprocal shaft 87 which may be keyed or otherwise secured to the disk-like body 86. The disk-like body 86 includes an upper surface 88, a lower surface 90 and a peripheral surface 91.

Three groups of rollers 92, 93 and 94 of three identical rollers or elongated elements in each group are secured to the disk-like body 86. Each group of rollers 92, 93 and 94 includes a first roller 95 adjacent the peripheral surface 91 of the disk-like body 86. A second roller 96 and a third roller 97 are each spaced from the first roller 95 and cooperate therewith to form a curved access area or passage for the reception of an edge 98 of a can body 100.

As is best illustrated in FIGURE 14 of the drawings, each of the rollers 95, 96 and 97 is rotatably carried in an aperture 101 of the disk-like body 86 by a shaft 102 having a flat head 103. Each of the rollers 9597 has a lower curved portion 104 which gradually blends into a peripheral portion 105.

The operation of the flexing head 85 is similar to that heretofore discussed in connection with FIGURES 1 through 3 of the drawings, except that the edge 98 of the can body is neither partially nor fully flanged. The can body 100 is held in a split holder 12 having a base 13 which is suitably anchored to a supporting surface 14. The flexing head 85 is rotated and reciprocated from a position spaced from the edge 98 of the can body 100 to the position illustrated in FIGURE 12. During the downward movement of the flexing head 85, the edge 98 of the can body 100 contacts the curved portion 104 of each of the rollers 95-97. The curved portions 104 of the rollers 95-97 form a trough which gradually narrows toward the bottom surface 90 of the disk-like body 86. This permits the edge 98 of the can body 100 to enter the access area or passage between the peripheral portions 105 of the rollers 95-97. As the disk-like body 86 is rotated, the edge 98 of the can body 100 is subjected to rapidly reversing tension and compression forces along incremental portions thereof. This causes stretching or elongation of the relatively brittle metal of the edge 98 for the reasons heretofore discussed. However, at the completion of this operation, the can body 100 is neither partially nor fully flanged. That is, after the flexing head 86 is withdrawn, the can body 100 and the edge 98 thereof are still relatively cylindrical in cross-section. The can body 100 can be shipped in this relatively cylindrical shape and conventional flanging apparatus which would otherwise be incapable of flanging the can body 100 may be employed to flange the edge 98 of the can body 100.

Another flex-flanging or spin flanging head constructed in accordance with this invention is illustrated in FIG- URES 15 through 17 of the drawings and is generally designated by the reference numeral 106. The spin flanging head 106 includes a body 107 provided with a substantially frustoconical cavity 108 and an axial bore 110. A rotatable shaft 111 having a stop collar 112 and a threaded end portion 113 is received in the bore of the body 107. A cylindrical steel core 114 is slipped on the reduced end portion 113 of the shaft 111 by virtue of an axial bore 115 in the core 114. The core 114 is provided with a plurality of elongated grooves or slots 116 arranged equally about the periphery of thh core 114. An identical elongated element or insert 118 is housed in each of the elongated grooves or slots 116 and projects outwardly beyond a peripheral surface 117 of the core 114. The inserts 118 are preferably constructed from carbide or nylon and each insert includes a gradually upwardly tapering curved portion 120 terminated in a contoured annular portion 121. A bottom beveled edge 122 of each of the inserts 118 engages an upper surface 123 of a substantially frustoconical clamping plate 124. The clamping plate 124 has a bore 125 in axial alignment with the bores 110 and 115. The threaded end portion 113 passes through the bore 125 of the clamping plate 124 and a nut 126 clamps the plurality of inserts 118 between the body 107 and the clamping plate 124 of the spin flanging head 106.

Once again, the operation of the spin flanging head 106 is substantially identical to the operation of the flexing and spin flanging heads heretofore described. A can body 127 having an edge 128 is secured in a split holder 12 having a base 13 suitably anchored to a supporting surface 14. The can body 127 is held in axial alignment with the spin flanging head 106. As the spin flanging head 106 is rotated and reciprocated downwardly, as viewed in FIGURE 15, into the can body 127, incremental portions or areas of the edge 128 are subjected to reversing tension and compression forces. This is best illustrated in FIGURE 16 of the drawings where at any one instant an incremental area or portion I of the can body edge 128 is being formed and the rotation of the spin flanging head 106 progressively moves this incremental area I rapidly around the can body 127.

It should be again noted that the tapered surfaces 120 of the inserts 118 present a small arc of contact to the edge 128 of the can body 127. The tapering surfaces 120 effectively reduce the area of contact in the manner similar to that discussed in connection with FIGURES 1 through 3 of the drawings.

When the spin flanging head 106 has been fully descended into the can body 127, as shown in FIGURE 17, the can body edge 128 gradually curves outwardly because of the contoured annular portion 121 of each of the inserts 118. The spin flanging head 106 thus flexes and forms a flange which is normal to the axis of the can body 127.

A flexer or flexing head 130 is shown in FIGURES 18 through 21 of the drawings. The flexing head 130 includes a body 131 having a frustoconical surface or portion 132 defined by a generatrix of the body 131. The body 131 is immovably secured to a supporting surface 133 by a plurality of identical bolts 134 in the manner clearly illustrated in FIGURE 20.

A plurality of equally spaced grooves or slots 135 are formed in the frustoconical surface 132 of the body 131. A substantially cylindrical, elongated element or insert 136 is non-rotatably carried in each of the grooves 135. Each of the cylindrical insert 136 includes a curved surface portion 137 projecting outwardly beyond the frustoconical surface 132 of the body 131. Each of the cylindrical inserts 136 is also axially aligned with the generatrix of the body 131.

The flexing head 130 is axially aligned with a can body 138 having an edge 140. The can body 138 is held in a split holder 141 secured to a base 142. A shaft 143 of the base 142 is rotated and reciprocated in a conventional manner.

As the shaft 143 is moved upwardly, as viewed in FIGURE 18, the can body edge 140 contacts the curved surface portions 137 of the inserts 136. Each of the cylindrical inserts 136 again subjects an incremental portion or area of the edge 140 of the can body 138 to rapidly reversing tension and compression forces as the base 142 and the can body 138 carried thereby is rotated. The edge 140 of the can body 138 is flexed in a manner substantially identical to that heretofore described in connection with FIGURES 1 through 3 of the drawings. It should be noted that the position of the cylindrical inserts 136 flex the edge 140 of the can body 138 radially inwardly toward the axis of the can body 138. Thus, at

12 the end of the flexing operation and the upwardly removal of the flexing head 130, the can body 138 will be partially flanged inwardly at an angle of approximately 45 degrees. Any can body so conditioned or flexed can now be fully circumferentially flanged without cracks developing in the flange area.

FIGURE 22 illustrates a roll flanger 145 in which a relatively brittle can body may be formed with a circumferential flange of ninety degrees after the can body edge has been flexed by any one of the flexing devices heretofore disclosed. The roll flanger 145 includes a body 146 provided with a bore 147 having a diameter substantially equal to the external diameter of a can body 148. An axially opening circumferential groove 150 is formed in the body 146 of the roller flange 145.

A roll 151 is housed in the body 146 of the roll fianger 145. The roll 151 includes a cylindrical body 152, a circumferential flanging rib 1 53 and a shaft 154. The shaft 154 is part of a conventional mechanism which rotates and eccentrically moves the flanging rib 153 about and within the peripheral groove 150. During this movement, an edge 155 of the cam body 148 is flanged a full ninety degrees with respect to the axis of the can body.

A spin flanging head has been constructed in accordance with the FIGURES 6 through 9 disclosure and the FIGURES 10 through 11 disclosure, and has been tested with the following results.

The spin flanging heads of FIGURES 6 through 11 were tested on can bodies constructed of different metals varying in ductility, strength, temper and grain direction. These metals will be referred to hereafter in conventional can making terminology.

Most of the testing has been done on can bodies constructed from 55# tube welded T-8 plate made from aluminum killed or MR-type steel which has been cold rolled 3050% after annealing. Several hundred of these can bodies were successfully flanged to the normal can end receiving flange width of 0.105 inch, using the spin flanging head with ten inch diameter rollers. Can bodies constructed from identical material and tested by dynamic die flanging heads invariably cracked in the area of the flange.

Approximately 300 C-grain can bodies with soldered side seams made from 35 lb./bb. (0.10 mm.) T-8 plate, were spin flanged with the spin flanging head having ten tantalum carbide rollers. These can bodies were subsequently packed and double seamed on a #449 closing machine at a speed of 1,160 cans per minute. No leaks developed in the can body or the flange area when these cans were packed in cartons of 24 cans per carton and test dropped from a height of 10 feet.

Can bodies constructed from 45 1b./bb. (0.12 mm.) full hard plate, i.e., hot mill strip cold rolled to final gauge without an interanneal, was more diflicult to spin flange. With I-I-grain spot welded cylinders of a 2 inch diameter, flanges up to a width of 0.070 inch were consistently formed without cracking.

70 lb./bb. (0.20 mm.) full hard plate, H-grain was flanged to a Width of .090 inch with the spin flanging head having the ten A inch diameter rollers.

100 lb./bb. (0.27 mm.) full hard H-grain plate was flanged to the normal can end receiving width of .105 inch. Can bodies constructed from aluminum alloys such as 3003 (1.25% Mn) and 5052 (2.5% Mg, 0.25% Cr) in intermediate and full hard tempers, were flanged successfully with both the spin flanging head having the inch diameter rollers and the three l-inch diameter rollers.

The spin flanging head with the ten inch diameter rollers was tested under various conditions employing can bodies fabricated from different sheet materials. In certain tests some of the ten rollers were removed leaving the spin flanging head with five or two rollers. With this reduction in the number of rollers, a correspondingly high number of rotations had to be made in order to make a smooth flange. As heretofore noted, with fewer rollers it was also necessary to support the can body near to the edge in order to avoid polygonization and cracking. In the extreme case of two rollers with very brittle double reduced, H-grain can bodies, flange cracks develop when more than 0.150 inch of the body edge was left unsupported. With ten rollers, rigid support was at times not necessary at all and good flanges were obtained even when the can bodies were held by hand.

The spin fianging head with the three l-inch rollers (see FIGURES and 11) was also tested under various conditions. With this spin fianging head the split holder always had to be moved as close to the edge of the can body as possible to avoid distortion of the can body. However, this spin flanging head worked well with aluminum bodies which could be flanged under widely different conditions as compared to double reduced or T-8 plate, where fianging conditions are more critical.

The rotational speeds of the spin fianging heads as well as the advancement of the spin fianging heads into the can bodies were varied considerably. In a typical test where a can body was fabricated from 55 lb./bb. T-8 tinplate welded tube, the can body was flanged at a rotational speed of 640 r.p.m., and advanced into the can body at a speed of 1.04 inch per second. A normal can end receiving flange .105 inch-wide was completed in 0.14 second, i.e., less than two revolutions of the spin fianging head. Since both the rotational and the entry or advancement speed of the spin fianging end can be increased, this 0.14 second time interval can be measurably reduced making it possible to spin flange can bodies at the rate of 400-600 can bodies per minute.

From the foregoing, it will be seen that novel and advantageous provision has been made for fianging can bodies which have heretofore been incapable of being flanged by conventional fianging apparatus. While the flexing heads herein disclosed make possible the flexing and fianging of relatively brittle can bodies, attention is again directed to the fact that variations may be made in the example flexing and spin fianging heads disclosed herein without departing from the spirit and scope of this invention as defined in the appended claims.

I claim:

1. A method of fianging tubular can bodies constructed of relatively thin metallic material comprising the steps of providing a rotatable fianging head having a plurality of generally conical rollers Whose axes are at all times equally radially spaced from the axis of rotation of the fianging head and in substantial parallel relationship and which each include a peripheral surface curved radially outwardly to define a generally annular outwardly opening smooth shoulder, roviding a can body of relatively thin metallic material and of a normally circular transverse cross-sectional configuration, supporting the can body so as to leave at least one circumferential end portion of the can body at all times free and unsupported, providing relative rotation between the fianging head and the can body, providing axial relative movement between the fianging head and the can body whereby the rollers of the fianging head are progressively introduced into and against an interior surface of the one circumferential end portion of the can body, said conical rollers being effective to initially direct a plurality of forces against the inner surface of the unsupported end portion to effect rapidly reversing tension and compression forces in incremental surface areas of the unsupported end portion whereby the outer surface of the circumferential end portion is first strained beyond the yield point during the tension portion of the reversing cycle and the normal circular transverse configuration thereof is transformed at least temporarily to a generally polygonal cross-sectional configuration, and thereafter subjecting the end portion to forces imposed by the shoulder which cause only circumferential deformation whereby the end portion is radially outwardly flanged during the time it is subjected to said circumferential deformation by the shoulder whereby the end portion is transformed into a flange in the absence of flange cracking and performing the latter step in the absence of any exterior support of the exterior surface of the unsupported end portion.

2. A method of fianging tubular can bodies constructed of relatively thin metallic material comprising the steps of providing a rotatable fianging head having a plurality of generally conical rollers whose axes are at all times equally radially spaced from the axis of rotation of the fianging head and in substantial parallel relationship and which each include a peripheral surface curved radially outwardly to define a generally annular outwardly opening smooth shoulder, providing a can body of relatively thin metallic material and of a normally circular trans verse cross-sectional configuration, supporting the can body with its axis in coaxial relationship to the axis of rotation of the rotatable fianging head and so as to leave at least one circumferential end portion of the can body at all times free and unsupported, providing relative rotation between the fianging head and the can body, providing axial relative movement between the fianging head and the can bod whereby the rollers of the flanging head are progressively introduced into and against an interior surface of the one circumferential end portion of the can body, the conical rollers being effective to initially direct a plurality of forces against the inner surface of the unsupported end portion to effect rapidly reversing tension and compression forces in incremental surface areas of the unsupported end portion whereby the normal circular transverse configuration thereof is transformed at least temporarily to a generally polygonal cross-sectional configuration, thereafter subjecting the one end portion to forces imposed by the shoulder causing the end portion to be directed radially outwardly into a flange during the time it is in contact with the shoulder, performing the latter step in the absence of any exterior support of the exterior surface of the one end portion, and providing axial relative movement between the flanging head and the can body whereby the rollers of the flanging head are withdrawn from the one end portion of the can body and the latter resumes its initial normally circular transverse cross-sectional con-figuration.

3. A method of fianging tubular bodies comprising the steps of supporting a tubular body at a major body portion thereof so as to leave a minor circumferential end portion of the body at all times free and unsupported, providing a space between the point at which the tubular body is supported and the juncture point between the tubular body and a flange to be formed generally normal thereto, providing relative rotation between the tubular body and a fianging head, providing relative axial movement between the tubular body and the fianging head to progressively direct the minor circumferential end portion radially outwardly while also maintaining the minor circumferential end portion continually free and unsupported, and working the material of the minor circumferential end portion beyond its elastic limit as it is progressively directed radially outwardly by directing a plurality of forces against the minor circumferential unsupported end portion to effect rapidly reversing tension and compression forces in incremental areas of the unsupported end portion whereby the end portion is transformed into a flange in the absence of polygonization and cracking of the flange.

4. The method of fianging as defined in claim 3 wherein the fianging head has a plurality of rollers, and during said relative rotational and axial movement, interiorly contacting the minor circumferential end portion with the rollers to thereby effect rapidly reversing tension and compression forces in incremental areas of the unsupported 5. The method of fianging as defined in claim 3 wherein the tubular body is formed of metallic material of a tensile elongation not in excess of 1.5% When measured over a normal gauge length of 2 inches.

6. The method of flanging as defined in claim 4 comprising the step of straining the outer surface of the minor circumferential end portion beyond the yield point during the tension portion of the reversing cycle, and thereafter subjecting the minor circumferential end portion to forces causing only circumferential deformation.

7. The method of flanging as defined in claim 6 wherein the tubular body is formed of metallic material of a tensile elongation not in excess of 1.5% when measured over a normal gauge length of 2 inches.

References Cited UNITED STATES PATENTS FOREIGN PATENTS Germany. Germany. France. France.

Great Britain.

15 RICHARD J. HERBST, Primary Examiner US. Cl. X.R. 

3. A METHOD OF FLANGING TUBULAR BODIES COMPRISING THE STEPS OF SUPPORTING A TUBULAR BODY AT A MAJOR BODY PORTION THEREOF SO AS TO LEAVE A MINOR CIRCUMFERENTIAL END PORTION OF THE BODY AT ALL TIMES FREE AND UNSUPPORTED; PROVIDING A SPACE BETWEEN THE POINT AT WHICH THE TUBULAR BODY IS SUPPORTED AND THE JUNCTURE POINT BETWEEN THE TUBULAR BODY AND A FLANGE TO BE FORMED GENERALLY NORMAL THERETO, PROVIDING RELATIVE ROTATION BETWEEN THE TUBULAR BODY AND A FLANGING HEAD, PROVIDING RELATIVE AXIAL MOVEMENT BETWEEN THE TUBULAR BODY AND THE FLANGING HEAD TO PROGRESSIVELY DIRECT THE MINOR CIRCUMFERENTIAL END PORTION RADIALLY OUTWARDLY WHILE ALSO MAINTAINING THE MINOR CIRCUMFERENTIAL END PORTION CONTINUALLY FREE AND UNSUPPORTED, AND WORKING THE MATERIAL OF THE MINOR CIRCUMFERENTIAL END PORTION BEYOND ITS ELASTIC LIMIT AS IT IS PROGRESSIVELY DIRECTED RADIALLY OUTWARDLY BY DIRECTING A PLURALITY OF FORCES AGAINST THE MINOR CIRCUMFERENTIAL UNSUPPORTED END PORTION TO EFFECT RAPIDLY REVERSING TENSION AND COMPRESSION FORCES IN INCREMENTAL AREAS OF THE UNSUPPORTED END PORTION WHEREBY THE END PORTION IS TRANSFORMED INTO A FLANGE IN THE ABSENCE OF POLYGONIZATION AND CRACKING OF THE FLANGE. 